Helicopter



May 15, 1923. 1,455,352

A. OVERBEEK HELICOPTER Sheets-Sheet l Filed Dec. l, 1921 Per www May 15, 1923. 1,455,352

- A. OVERBEEK HELICOPTER Filed DeC. l. 1921 3 Sheets-5116.815 2 /nrenor May 15, 1923. 1,455352` A. OVERBEEK HELICOPTER Filed Dec. l. 1921 5 Sheets-Shee'f,` 5

20 sil fill/111111111' ?atented May l5, i923.

mars-so STATES PATENT OFFICE.

HELICOPTER.

I Application filed December 1, 1921. Serial No. 519,116.

To all whom it may concern:

Be it known that ALBERTUS OVERBEEK, a citizen of thev Dutch East Indies, and resident of Weltevreden, Java, Dutch East Indies, have invented certain new and useful Improvements in a Helicopter, of which the following is specification.

The invention relates to a helicopter with two propellers rotatable in opposite direction and particularly to the transmitting gear between motors and propellers,

It has been proved necessary with aerial machines of this kind to provide means for preventing the turning of the machine about its vertical axis which is caused by the action of the Propellers. Hitherto this has been overcome by means of the rudders, but this absorbs much power.

According tothis invention the solution of the question is accomplished by driving each of the propellers with a different speed and 1n such a way that the resistance of the air met during the rotation isequal.

propellers so that they can be adjusted simultaneously to the desired speed.

According to the invention the propellers are for this purpose arranged on concentric shafts, which are provided at their lower ends with friction discs, which cooperate with one or more motor driven discs.

The adjustment of the propeller-s is effected by `means of an adjustable nut, ar-

' ranged in the frame of the propeller shafts,

which nut co-acts with a screwthreaded part of the outer hollow shaft, the latter acting on the inner propeller shaft for instance by means of a collar fixed on the same.

To propel the helicopter in a forward direction, the center of gravity of the helicopter-hull must be put more to the bow, by moving a special weight ad'usted in or under the hindpart of the hul or by shifting to the front of any movable load and passonger-seats inside the hull, after this the whole gear must be adjusted in an inclined position, for which purpose the gear is arranged in a casing, rotatably mounted about a horizontal axis in the hull and guided in separated guides therein, and which housing can belocked or held in' any desired po.- sitlon. By putting the centre of gravity more to the hindpart of the hull, the helicopter moving in forward direction can be stopped quickly.

This can be attained bv connecting the In the drawings, which show by way of illustration an embodiment ofthe invention:

Fig. 1 1s a part vertical section of allelicopter, the propellers being omitted, Fig. 2 is a side view of the gear for adjusting and driving the propellers, one side of the hull being broken away.

Fig.y 3 shows a larger scale, a part longitudinal section of the propeller shafts and driving gear.

Fig. 4 is a 4vertical section of the motor friction disk and Figs. 5, 6 and 7 are side, front `and plan views respectively of another form of construction, of the driving gear for the propellers.

The helicopteris of the type having two propellers a and I) rotating in opposite direction. The whole transmitting gear to adjust and drive the propellers is arranged in a cylindrical casing 1, which is rotatable about hollow journals. 3, mounted in the `hull 4of the aerial machines and carried by dovetailed flanges 5 in guides 6 of the hull.

'It is also possible to adjust rthe motors in or upon the hull and to make pivotable only the frame connected with the transmitting gear and propellers about hollow journals mounted in the hull. The centre of thesehollow journals must correspond with the centre of the friction axles (or bevel wheels) turned by the motors.

The casing 1 is provided in the middle with a ytoothed sector 7 with which a` worm 8 meshes. This worm is fixed on an axle 10 with handwheel 9, which axle rests in `bearings 11 and 12, attached to iron frames of the hull 4. The hollow journals 3 are as exactly as possible placed above the cen*- tre of gravity of the' hull. Between the bottom of the housing` land the hull is a space 2, which may,V be preferably used to store fuel, water and accumulators for driv ing the reserve electrical motorlS.

For the normal driving of the Propellers, an internal combustion motor 13 having sixv radially disposed cylinders, or a motor of other suitable type is provided which may be fixed in any suitablel manner in the housllo - by meahs ofa key (Fig. 4

propeller b 1s ner. In the cup thus formed, a ball-bearing ring 28' mounted on the crankshaft 14 and locked Thefriction by disc is ressed inwardy means of a spring 5, lbearlng with its other end a ainst a -collar 6 on 'the crankshaft.

ese levers 16 are referably arranged in vsuch a manner that 1n the vertical position of the transmitting gear the loyers extend horizontally, so that same are always easy to actuate opposite this friction-disk 15 is mounted a similar disc 17 which is simi-4 larly connected with the reserveV electrical motor 18 and can be actuated in a simllar manner.

Besides the arrangement of a combustlon and an electrical motor, can be mounted two combustion motors, and when they cooperate, only half the force of each motor is needed as compared withtheir normal4 working capacity.

So as to ensure uniform pressure of the disks 15 and 17 on the friction discs 21 and 22, the end of the clutch box is spherically shaped and provided with a ball 45, which fits in a corresponding socket on the disc. bearing. The spherical end or ball 45 1s fixed in this bearing by a divided ring 46. The friction-discs 21 and 22 are pushed from below along a portion of therespective shafts, which are of less diameter, and locked thereon by a nut. It is obvious that the discs can be fixed in any other suitable way.

The propellers a and b, rotating in opposite direction are as already mentioned. mounted on concentric shafts 19 and 20 (Fig. 3) provided at their lower ends with discs 22 and 21, arranged between and adapted to cooperate with one of the discs or'with both. o

The shafts 19 (Fig. 3) extends downported in a bearing 23 of the housin 1. etween thev two frictiondiscs 21 and 22 is another bearing 24 adapted to guide the shaft 19, which bearing is connected by suitable means to the casing. It is possible to omit the bearing 23 as indicated vin Fig..1.' The shaft 19 can also slide in this bearing. The upper end of the outer hollow shaft 20 has its wall rectangular and bent outwardly to form a Hange or collar 25, on which collar a perpendicular flange 26 is provided to form a cupA (Fi 3); on said fian e 26 the tted in any suita le manwardly and is su is mounted consisting` of a bottom i with an upper gland 27, between which ring and bottom ring 1 inner massive shaft 19 a.

gland `the balls are arranged. The 28 bears on a fiange 29 of the of the` upper propeller The hollow shaft 20 bearsfin thek same -the latter being provided Ion an axle 57 of the propeller b" -made with V,help of lthrough the medium of th .fromthe bevel wheel 48` This flange 29 bea-rs on a horizontal.`

manner as theinner-shaft bears in the outer,

cup of the box 31,

The ybottom ring 33 of this ball-bearingis n also divided. In order to make poss the mounting of the parts and to avoid divided rings and glands, thecollar 30 must be screwed on the hollow shaft. The box 32 is slidably but not rotatably mounted in a sleeve 34 and locked by means of key 35. This sleeve 34 is also divided and is fixed wlth studs 36 in a strut 37 of the frame 38, with lugs, through which the frame'columns 39 extend and are attached by their lower ends to the casing. The hollow box 31 has a screw-threaded part at its lower end, along which a nut 1s movable, the latter being rotatably suspended by a ring 41 and bolts 42 on a flange of the sleeve 34. The hollow box 31 is prevented from backward rotation by a locknut 43. By rotatlng the nut 40, the box 31 and through 1t the shafts of the propellers are adJusted up and down. A lflange 44 is screwed at the underendy of the box 31 for' strengthening purposes.v

To adjust the speed of the propellers durug runmng, the outer edge of the nut 40 `lgs. 1 and 2) 1s provided with wormteeth, 1n which engages a worm 56 fixed with a chain wheel 58. This chain wheel is connected by a chain 59 to a chainwheel 60, mounted on the same axle as a chain wheel 61 this axle being held in a caslng 1n any suitable manner. Chainwheel 61 is actuated by a chain 62, chain wheel 63 and hand wheel 64. By actuating the hand wheel 64 it ispossible to actuate the ynut v40 and toadjust the friction discs 21 and 22.

As the nut 40 is controlled by lock-,nut can be omitted. The` axle 57 of the worm 56-is journalled in two bearings 65 and 66 carried by a cross member 67 clamped to the columns 39.

InFigs. 5, 6 and 7 a form of construction of thev gear is illustrated which consists of toothed and bevel gear.

The proportion'of the `respective numbers of rotation of each mined a worrn the by means of experiments previously the lfriction gean. (Figs.1-4). f

Referring to Figs. 5 to 7, the hollow shaft 20 of the lower propeller is driven e bevell wheel 51 (or 49) on the motor shaft 46 l(or 47) and the lbevel wheel 50 is mounted independently of the shaft 19 of the upper ypropeller andA has a spur wheel 52 adapted to rotate therewith. Freely mounted upon the said shaft19 isa gear propeller must be deterwheel 53 in mesh with a wheel 55 fixed upon the same shaft as another kwheel 54 which latter is thusrotated simultaneously with the wheels 53, 55'and which meshes with the said spur wheel 52. Between the bevel Wheel and the wheel 53 a sliding clutch member is keyed on the shaft 19 (see particularly Fig. l5), and is adapted to frictionally engage either the bevel wheel 50 or the wheel 53 so that the rotary motion ofthe bevel wheel 48 (or 49) is transmitted to the propeller shaft 19 either directly through the friction clutch device from the wheel 50 or through the said friction clutch device and through the wheels 53, 55, 54 and 52 to 'the said wheel 50, in the latter case the wheel 53 rotating idly upon the shaft 19. It will thus be seen that whilst the wheels 50, 53 are rotated constantly at dierent speeds the propeller shaft 19 may be coupled up to one or the other so as to vary the speed of the upper pro eller relatively to that of the lower prope ler, whose speed remains constant.

n the hull is provided a stop 68 to limit the deflection of the transmitting gear `from the vertical position.

The hull of the helicopter is carried by two shafts 60 and 70, to which the landing Wheels 71 are attached; to prevent the wheels rotating too easily wihch is objectionable for starting on a slope, these shafts are provided with friction discs 72, which cooperate with the friction discs 73 of the landing wheels. By pressing those discs more or less together by means of nuts 74, the friction of the wheels' on the shaft can be controlled.

A usual brake construction can also be em loyed.

it is obvious that, the motors, friction described my invenspeeds, and means whereby the propeller shafts can be inclined in the forward and the rearward direction of the apparatus'.

2. In a helicopter as lclaimed in claim 1, means for the adjustment of the speed of the Propellers comprisin a sliding sleeve connected with the propeer frame and carrying hollow concentric shafts, anda rotatable nut mounted on the sleeve for operating same.

3. ln a helicopter as claimed in claim 2, outer worm teeth on the rotatable nut, a worm-wheel en aging said teeth, and mechanism mounte in the hull for operating said worm-wheel.

4. In a helicopter as claimed in claim 1, a casing enclosing the driving gear, and mounted in the hull so as to move about a horizontal axis, and means for holding the casing in adjusted position.

In 'testimony whereof, I have signed my name to this s eciiication in the presence of two subscribing witnesses.

ALBERTUS OVERBEEK.

Witnesses:

R. H. ToMrmNs, MILLARD L. THOMAS. 

